Coexistence mechanism for WiMAX and IEEE 802.11

ABSTRACT

A network device includes a first communication module and a second communication module. The first communication module communicates with a first device using a first wireless communication standard. The first communication module receives data from the first device during a first time period and transmits data to the first device during a second time period. The second communication module communicates with a second device using a second wireless communication standard. The second communication module receives a block of packets from the second device during the first time period. The second communication module transmits an acknowledgement to the second device during the second time period when the block of the packets is received.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/388,831 filed on Feb. 19, 2009. This application claims the benefitof U.S. Provisional Application No. 61/039,931, filed on Mar. 27, 2008.The disclosure of the above application is incorporated herein byreference in its entirety.

FIELD

The present disclosure relates to wireless network devices, and moreparticularly to devices that communicate using multiple communicationstandards.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent the work is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

Referring now to FIG. 1, a handheld wireless network device (device) 100may comprise an antenna 102, an antenna sharing module 103, a firstcommunication module 104, and a second communication module 106. Thefirst and second communication modules 104, 106 may communicate usingdifferent wireless communication standards (standards). Accordingly, thedevice 100 is said to communicate using collocated communication modulesthat use different communication standards.

For example only, the first communication module 104 may communicateusing a Fourth Generation (4G) standard or a Bluetooth® (BT) standard.The 4G standard may include Worldwide Interoperability for MicrowaveAccess (WiMAX), Third Generation Partnership Project (3GPP) Long TermEvolution (LTE), or Ultra Mobile Band (UMB) standard. Throughout thedisclosure, the WiMAX standard is used as an example only. However, thediscussion is applicable to other 4G standards and the BT standard.

The second communication module 106 may communicate using one of theI.E.E.E. 802.11 communication standards. For example only, the secondcommunication module 106 may communicate using a wireless fidelity(WiFi) standard that uses the I.E.E.E. 802.11 specification.Alternatively, the second communication module 106 may communicate usingBT with an Alternative Medium access controller (MAC) and Physical layer(PHY) (i.e., BT-AMP) technology. The BT-AMP technology enables BT tosupport data rates of up to 24 Megabits per second (Mbps) and increasesrange by using other wireless radio technologies, such as the I.E.E.E.802.11, as transport medium.

The first communication module 104 using one of the 4G standards (e.g.,the WiMAX standard) typically communicates via 2.5 GHz and 2.3 GHzfrequency bands. The second communication module 106 typicallycommunicates via the Industrial, Scientific, and Medical (ISM) frequencyband of 2.4GHz. The first and second communication modules 104, 106 mayshare the antenna 102 via the antenna sharing module 103. Although theantenna 102 is shown as a single antenna, the device 100 may comprisemultiple antennas that may be shared by the first and secondcommunication modules 104, 106. Accordingly, data received by the firstcommunication module 104 may occasionally interfere with the datatransmitted by the second communication module 106, and vice versa.

For example, data received by the first communication module 104 from aWiMAX base station (BS) (not shown) may interfere with data transmittedby the second communication module 106 to a remote WiFi device (notshown). The remote WiFi device may include an access point (AP) or aclient station. The interference may cause the WiMAX BS to drop the datarate of transmission. Dropping the data rate may increase the durationof the transmitted packets. Increasing the duration of the transmittedpackets may, in turn, increase the interference. If the interferenceexceeds a predetermined threshold, the device 100 may be disconnectedfrom the WiMAX BS.

Additionally, data received by the second communication module 106 fromthe remote WiFi device may interfere with data transmitted by the firstcommunication module 104 to the WiMAX BS. The interference may cause theremote WiFi device to drop the data rate of transmission. Dropping thedata rate may increase the duration of the transmitted packets.Increasing the duration of the transmitted packets may, in turn,increase the interference. If the interference exceeds a predeterminedthreshold, the device 100 may be disconnected from the remote WiFidevice.

Referring now to FIG. 2, for example only, the interference betweenWiMAX and WiFi communications of the device 100 is discussed in detail.The device 100 transmits and receives WiMAX frames using the firstcommunication module 104. Each WiMAX frame comprises a downlink (DL)sub-frame that the device 100 receives and an uplink (UL) sub-frame thatthe device 100 transmits. Typically, the duration of the WiMAX frame isapproximately 5 ms, where the duration of the DL sub-frame isapproximately 3.5 ms, and the duration of the UL sub-frame isapproximately 1.5 ms.

Additionally, the device 100 also receives and transmits 802.11 packetsusing the second communication module 106. Typically, when the device100 receives an 802.11 packet, the second communication module 106transmits an acknowledgement (ACK) to the remote WiFi device indicatingthat the 802.11 packet is received by the device 100. If the 802.11packet is not received by the device 100, the second communicationmodule 106 does not transmit the ACK to the remote WiFi device. When theremote WiFi device does not receive the ACK, the remote WiFi devicelowers the data rate and retransmits the 802.11 packet.

If the remote WiFi device again does not receive the ACK from the device100, the remote WiFi device again lowers the data rate and retransmitsthe 802.11 packet. The remote WiFi device continues to lower the datarate until the device 100 receives the 802.11 packet as indicated by theACK received from the device 100. If the ACK is not received afterlowering the data rate below a predetermined threshold, the remote WiFidevice drops the link to the device.

Occasionally, although the device 100 receives the packet while thedevice 100 is receiving the WiMAX DL sub-frame, the device 100 may nottransmit the ACK to the remote WiFi device for various reasons. Forexample, the device 100 may not transmit the ACK because the device 100is configured (e.g., by an arbiter) to not transmit data using thesecond communication module 106 when the device 100 is receiving WiMAXdata. When the remote WiFi device does not receive the ACK, however, theremote WiFi device presumes that the device 100 did not receive the802.11 packet. Accordingly, the remote WiFi device lowers the data rate,increases the packet duration, and retransmits the 802.11 packet.

If the device 100 is still receiving WiMAX data, the device 100 againmay not transmit the ACK to the remote WiFi device. The remote WiFidevice again lowers the data rate and retransmits the 802.11 packet. Bynow, the device 100 may be transmitting the WiMAX UL sub-frame insteadof receiving the WiMAX DL sub-frame. Depending on the design of aradio-frequency (RF) front-end of the device 100 (not shown), the secondcommunication module 106 may not receive the 802.11 packet when thefirst communication module 104 is transmitting data. Accordingly, theremote WiFi device may drop the link to the device 100 instead oflowering the data rate and retransmitting the 802.11 packet. Thus, theinterference between the WiMAX and WiFi communications may adverselyaffect the performance of the device 100.

SUMMARY

A network device comprises a first communication module and a secondcommunication module. The first communication module communicates with afirst device using a first wireless communication standard. The firstcommunication module receives data from the first device during a firsttime period and transmits data to the first device during a second timeperiod. The second communication module communicates with a seconddevice using a second wireless communication standard. The secondcommunication module receives a block of packets from the second deviceduring the first time period. The second communication module transmitsan acknowledgement to the second device during the second time periodwhen the block of the packets is received.

In other features, a method comprises communicating with a first deviceusing a first wireless communication standard, receiving data from thefirst device during a first time period, and transmitting data to thefirst device during a second time period. The method further comprisescommunicating with a second device using a second wireless communicationstandard and receiving a block of packets from the second device duringthe first time period. The method further comprises transmitting anacknowledgement to the second device during the second time period whenthe block of the packets is received.

In still other features, a network device comprises a firstcommunication means for communicating with a first device using a firstwireless communication standard and a second communication means forcommunicating with a second device using a second wireless communicationstandard. The first communication means receives data from the firstdevice during a first time period and transmits data to the first deviceduring a second time period. The second communication means receives ablock of packets from the second device during the first time period.The second communication means transmits an acknowledgement to thesecond device during the second time period when the block of thepackets is received.

In other features, the first wireless communication standard includesone of Worldwide Interoperability for Microwave Access (WiMAX), ThirdGeneration Partnership Project (3GPP) Long Term Evolution (LTE), orUltra Mobile Band (UMB), and Bluetooth® standards. The second wirelesscommunication standard includes one of I.E.E.E. 802.11 standards.

In other features, the second communication means transmits lengths ofthe first and second time periods to the second device. The seconddevice transmits a request for the acknowledgment to the network devicebefore the first time period ends. The second communication meanstransmits data during the second time period. The network device furthercomprises an antenna that the first and second communication means sharewhen communicating with the first and second devices, respectively.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description, the claims and the drawings. Itshould be understood that the detailed description and specific examplesare intended for purposes of illustration only and are not intended tolimit the scope of the disclosure.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of a wireless network deviceaccording to the prior art;

FIG. 2 is a timing diagram of signals exchanged by the wireless networkdevice of FIG. 1, a WiMAX base station, and a remote WiFi deviceaccording to the prior art;

FIG. 3 is a functional block diagram of an exemplary wireless networkdevice according to the present disclosure;

FIG. 4 is a timing diagram of signals exchanged by the wireless networkdevice of FIG. 3, a WiMAX base station, and a remote WiFi deviceaccording to the present disclosure; and

FIG. 5 is a flowchart of an exemplary method for reducing interferencewhen the wireless network device of FIG. 3 communicates using multiplecommunication standards according to the present disclosure.

DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the disclosure, its application, or uses. For purposesof clarity, the same reference numbers will be used in the drawings toidentify similar elements. As used herein, the phrase at least one of A,B, and C should be construed to mean a logical (A or B or C), using anon-exclusive logical or. It should be understood that steps within amethod may be executed in different order without altering theprinciples of the present disclosure.

As used herein, the term module may refer to, be part of, or include anApplication Specific Integrated Circuit (ASIC), an electronic circuit, aprocessor (shared, dedicated, or group) and/or memory (shared,dedicated, or group) that execute one or more software or firmwareprograms, a combinational logic circuit, and/or other suitablecomponents that provide the described functionality.

The present disclosure relates to systems and methods for reducing theinterference that may occur when the handheld wireless network device(device) communicates using collocated communication modules that usedifferent communication standards (standards). Throughout thedisclosure, the Worldwide Interoperability for Microwave Access (WiMAX)standard is used as an example only. The teachings of the presentdisclosure are applicable to other Fourth Generation (4G) standards andthe Bluetooth (BT) standard.

For example only, the device may communicate with the WiMAX base station(BS) and the remote wireless fidelity (WiFi) device using the WiMAX andWiFi standards, respectively. The device may transmit to the remote WiFidevice a first time period during which the device receives the WiMAXdownlink (DL) sub-frame and a second time period during which the devicetransmits the WiMAX uplink (UL) frame. Accordingly, the remote WiFidevice may transmit 802.11 packets to the device during the first timeperiod while the device receives the WiMAX DL sub-frame. The remote WiFidevice may not transmit the 802.11 packets during the second time periodwhen the device transmits the WiMAX UL sub-frame.

Specifically, the remote WiFi device may transmit a block or a burst of802.11 packets to the device during the first time period withoutrequiring the device to transmit the acknowledgement (ACK) for every802.11 packet received. Instead, the remote WiFi device transmits theblock of 802.11 packets using a block ACK, where the remote WiFi deviceexpects to receive a block ACK from the device when the device receivesthe block of 802.11 packets.

The device may receive the block of the 802.11 packets while receivingthe WiMAX DL sub-frame. The device does not transmit ACKs to the remoteWiFi device for each 802.11 packet received in the block by the device.Instead, the device may transmit the block ACK to the remote WiFi devicewhen the device receives the block of the 802.11 packets.

Before the end of the first time period or before the beginning of thesecond time period, the remote WiFi device may transmit a block ACKrequest (BAR) to the device. Subsequently, the device may transmit theblock ACK to the remote WiFi device when the device transmits the WiMAXUL frame during the second time period. The device transmits the blockACK to the remote WiFi device if the device received the 802.11 packetstransmitted by the remote WiFi device. When the remote WiFi devicereceives the block ACK, the remote WiFi device determines that thedevice received the block of the 802.11 packets transmitted by theremote WiFi device.

Alternatively, the remote WiFi device may not transmit the BAR. Instead,the remote WiFi device and the device may be preconfigured such that thedevice transmits the block ACK to the remote WiFi device during thesecond time period without requiring the remote WiFi device to transmitthe BAR.

Thus, the interference is reduced by scheduling and receiving blocks of802.11 packets while receiving WiMAX UL sub-frames, not transmittingACKs for every 802.11 packet received, and transmitting block ACKs whiletransmitting WiMAX UL sub-frames. The interference decreases since thedevice transmits data concurrently using the WiMAX and WiFi standardsduring the first time period and receives data concurrently using theWiMAX and WiFi standards during the second time period.

Additionally, the system throughput increases. This is because thedevice receives the 802.11 packets in blocks during the first timeperiod, and the device may transmit other 802.11 data packets inaddition to transmitting the block ACK during the second time period.

Referring now to FIGS. 3 and 4, for example only, an exemplary device150 that communicates using WiMAX and WiFi standards according to thepresent disclosure is shown. FIG. 3 shows the exemplary device 150. FIG.4 shows a timing diagram of signals communicated by the exemplary device150, the WiMAX BS, and the remote WiFi device.

The exemplary device 150 comprises the antenna 102, the antenna sharingmodule 103, the first communication module 104, a second communicationmodule 152, and a control module 154. For example only, the firstcommunication module 104 communicates using the WiMAX standard. Thesecond communication module communicates using one of the WiFi standards(e.g., I.E.E.E. 802.11n). Accordingly, the exemplary device 150 is saidto communicate using collocated communication modules that use differentcommunication standards. Although the antenna 102 is shown as a singleantenna, the exemplary device 150 may comprise multiple antennas thatmay be shared by the first and second communication modules 104, 152.

The control module 154 comprises a scheduling module 156 and a blockacknowledgement module 158. The scheduling module 156 determines thefirst time period during which the second communication module 152 mayreceive the block of the 802.11 packets from the remote WiFi device.Additionally, the scheduling module 156 determines the second timeperiod during which the second communication module 152 may transmit theblock ACK to the remote WiFi device.

The scheduling module 156 determines the first and second time periodsbased on the communication standard used by the first communicationmodule 104. For example, when the first communication module 104 usesthe WiMAX communication standard, the first time period may beapproximately equal to the time during which the first communicationmodule 104 receives the WiMAX DL sub-frame (e.g., 3.5 ms). Additionally,the second time period may be approximately equal to the time duringwhich the first communication module 104 transmits the WiMAX ULsub-frame (e.g., 1.5 ms).

The second communication module 152 transmits the first and second timeperiods to the remote WiFi device. Accordingly, the remote WiFi devicedetermines when the exemplary device 150 is available to receive theblock of the 802.11 packets transmitted by the remote WiFi device andwhen the remote WiFi device may receive the block ACK from the exemplarydevice 150.

For example, the remote WiFi device determines that the exemplary device150 is available to receive the block of the 802.11 packets during thefirst time period and that the exemplary device 150 may transmit theblock ACK during the second time period. Accordingly, the remote WiFidevice schedules the transmission of the block of the 802.11 packets tothe exemplary device 150 based on the first and second time periods.

Specifically, the remote WiFi device transmits the block of the 802.11packets to the exemplary device 150 during the first time period. The802.11 packets may conform to the I.E.E.E. 802.11 standard format usedby the exemplary device 150 and the remote WiFi device. For example, the802.11 packets may include medium access controller (MAC) service dataunit (MSDU) packets, MAC protocol data unit (MPDU) packets, and so on.The 802.11 packets may be separated by a short inter-frame space (SIFS).

The block ACK module 158 generates a control signal when the secondcommunication module 152 receives the block of the 802.11 packets fromthe remote WiFi device during the first time period. The block ACKmodule 158 inputs the control signal to the second communication module152. The second communication module 152, in turn, transmits the blockACK to the remote WiFi device when the first communication module 104transmits the WiMAX UL sub-frame during the second time period.

Referring now to FIG. 5, steps of a method 200 for reducing interferencewhile communicating using multiple communication standards are shown.Control begins at step 202. Control determines the first time period ofthe WiMAX DL sub-frame in step 204. Control determines the second timeperiod of the WiMAX UL sub-frame in step 206. Control transmits thefirst and second time periods to the remote WiFi device in step 208.

In step 210, control receives the block of the 802.11 packets from theremote WiFi device while receiving the WiMAX DL sub-frame from the WiMAXBS. Control does not transmit ACKs to the remote WiFi device for each ofthe 802.11 packets received in the block in step 210. Control determinesin step 212 whether the block of the 802.11 packets were received. Ifthe result of step 212 is true, control transmits the block ACK to theremote WiFi device while transmitting the WiMAX UL sub-frame in step214.

Thereafter, or if the result of step 212 is false, control determines instep 216 whether any 802.11 packets are to be transmitted. If the resultof step 216 is true, control transmits 802.11 packets while transmittingthe WiMAX UL sub-frame in step 218. Thereafter, or if the result of step216 is false, control determines in step 220 whether the transmission ofthe WiMAX UL sub-frame is complete. If the result of step 220 is false,control returns to step 216. If the result of step 220 is true, controlstops the 802.11 transmission in step 222, and control returns to step210.

Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the disclosure can beimplemented in a variety of forms. Therefore, while this disclosureincludes particular examples, the true scope of the disclosure shouldnot be so limited since other modifications will become apparent upon astudy of the drawings, the specification, and the following claims.

What is claimed is:
 1. A network device, comprising: a first transceivermodule configured to (i) receive first data during a first time periodand (ii) transmit second data during a second time period using a firstwireless protocol; and a second transceiver module configured to (i)receive a plurality of packets during the first time period and (ii)transmit, in response to receiving the plurality of packets, a singleacknowledgement during the second time period using a second wirelessprotocol, wherein the first wireless protocol is different than thesecond wireless protocol.
 2. The network device of claim 1, wherein: thefirst wireless protocol conforms to one of Worldwide Interoperabilityfor Microwave Access (WiMAX), Third Generation Partnership Project(3GPP) Long Term Evolution (LTE), Ultra Mobile Band (UMB), andBluetooth® standards; and the second wireless protocol conforms to oneof I.E.E.E. 802.11 standards.
 3. The network device of claim 1, whereinthe second transceiver module is configured to transmit third dataindicating durations of the first time period and the second time periodto a remote device to allow the remote device to transmit the pluralityof packets to the network device during the first time period.
 4. Thenetwork device of claim 1, wherein the second transceiver module isconfigured to transmit third data indicating durations of the first timeperiod and the second time period to a remote device to allow the remotedevice to transmit a request for the single acknowledgment to thenetwork device (i) before the first time period ends or (ii) before thesecond time period begins.
 5. The network device of claim 1, wherein thesecond transceiver module is configured to transmit third data inaddition to the single acknowledgement during the second time period. 6.A method, comprising: receiving first data at a network device during afirst time period using a first wireless protocol; transmitting seconddata from the network device during a second time period using the firstwireless protocol; receiving a plurality of packets at the networkdevice during the first time period using a second wireless protocol;and transmitting from the network device, in response to receiving theplurality of packets, a single acknowledgement during the second timeperiod using the second wireless protocol, wherein the first wirelessprotocol is different than the second wireless protocol.
 7. The methodof claim 6, wherein: the first wireless protocol conforms to one ofWorldwide Interoperability for Microwave Access (WiMAX), ThirdGeneration Partnership Project (3GPP) Long Term Evolution (LTE), UltraMobile Band (UMB), and Bluetooth® standards; and the second wirelessprotocol conforms to one of I.E.E.E. 802.11 standards.
 8. The method ofclaim 6, further comprising: transmitting third data from the networkdevice to a remote device, wherein the third data indicates durations ofthe first time period and the second time period, and wherein the thirddata allows the remote device to transmit the plurality of packets tothe network device during the first time period.
 9. The method of claim6, further comprising: transmitting third data from the network deviceto a remote device, wherein the third data indicates durations of thefirst time period and the second time period, and wherein the third dataallows the remote device to transmit a request for the singleacknowledgment to the network device (i) before the first time periodends or (ii) before the second time period begins.
 10. The method ofclaim 6, further comprising transmitting, from the network device, thirddata in addition to the single acknowledgement during the second timeperiod.